Global Patent Index - EP 0084709 A1

EP 0084709 A1 19830803 - Embedded servo track following system and method for writing servo tracks.

Title (en)

Embedded servo track following system and method for writing servo tracks.

Title (de)

Spurnachlaufsystem mit eingebettetem Servoformat und Verfahren zur Servospurenaufzeichnung.

Title (fr)

Système d'alignement sur une piste utilisant un format d'asservissement intégré et méthode pour enregistrer des pistes servo.

Publication

EP 0084709 A1 19830803 (EN)

Application

EP 82306357 A 19821130

Priority

US 33085581 A 19811214

Abstract (en)

The system includes positioning means energizable for moving the read/write head to preselected recording positions relative to the disc and drive means for creating relative movement between the disc and the read/write head thereby enabling the transfer of data between the storage medium and the head. A plurality of servo tracks are embedded or recorded in servo data sectors on the disc for identifying preselected radial positions or informational data tracks on the disc. The servo data tracks are provided with a nonuniform radial track density. The track density of the servo tracks varies from more dense at the periphery of the disc to less dense at the interior of the disc. The radial track density of the servo data tracks is established with a method of writing embedded servo data that allows the unique performance characteristics of the moving read/write head to determine the actual spacing of the tracks. A clock track is written by writing a single pulse on a fixed clock track head, phase-lock looping to an intermediate clock track, which is written on a moving read/write head, and then phase-lock looping up to the final clock track which is written on the fixed clock track head. Radial track density is then determined by moving one of the read/write heads to a limit stop and writing a reference track.

IPC 1-7

G11B 5/58; G11B 21/10; G11B 5/012

IPC 8 full level

G11B 5/012 (2006.01); G11B 5/596 (2006.01); G11B 21/10 (2006.01)

CPC (source: EP KR US)

G11B 5/012 (2013.01 - EP US); G11B 5/59616 (2013.01 - EP US); G11B 5/5965 (2013.01 - EP US); G11B 21/10 (2013.01 - KR)

Citation (search report)

  • [YD] EP 0034938 A2 19810902 - NORTHERN TELECOM INC [US]
  • [Y] DE 1223420 B 19660825 - PHILIPS PATENTVERWALTUNG
  • [A] US 3924268 A 19751202 - MCINTOSH ROBERT P, et al
  • [A] US 4074326 A 19780214 - SMITH DOUGLAS A
  • [A] EP 0018157 A1 19801029 - BURROUGHS CORP [US]
  • [A] US 2901737 A 19590825 - STOVALL JR JOHN REED
  • [A] PATENTS ABSTRACTS OF JAPAN, vol. 5, no. 21(P-48)[693], 7th February 1981; & JP - A - 55 150 109 (FUJITSU K.K.) (21-11-1980)
  • [A] IBM TECHNICAL DISCLOSURE BULLETIN, vol. 12, no. 12, May 1970, pages 2366-2368, New York (USA);
  • [A] IEEE TRANSACTIONS ON MAGNETICS, vol. MAG-14, no. 5, September 1978, pages 327-329, New York (USA);
  • [A] IBM TECHNICAL DISCLOSURE BULLETIN, vol. 23, no. 10, March 1981, pages 4688-4689, New York (USA);

Designated contracting state (EPC)

DE FR GB IT NL SE

DOCDB simple family (publication)

EP 0166461 A2 19860102; EP 0166461 A3 19870520; CA 1191255 A 19850730; DE 3275446 D1 19870319; EP 0084709 A1 19830803; EP 0084709 B1 19870211; JP S58150174 A 19830906; KR 840003113 A 19840813; KR 910000539 B1 19910126; US 4414589 A 19831108

DOCDB simple family (application)

EP 85108976 A 19821130; CA 413636 A 19821018; DE 3275446 T 19821130; EP 82306357 A 19821130; JP 21563182 A 19821210; KR 820005574 A 19821213; US 33085581 A 19811214